Our Wilwood Superlite brake kit has always been one of our favorite parts of our C5 Corvette Z06, but nearly three years of hard use had finally ended our first set of 20mm-thick pads. Really, we can’t complain. That represents dozens of track events, time trials and autocrosses, so for the pads to finally be thinner than their ideal service size was perfectly acceptable. They earned it.
[Bigger brakes for our Corvette | Project C5 Corvette Z06]
And, truly, our Wilwood BO30-compound pads weren’t “done,” just ready for renewal. They still had a few usable millimeters of thickness left, and they produced just as much deceleration force once they grabbed the calipers as they did when they were new.
But that second part is important, because the pads were beginning to taper–fully typical behavior for pads nearing the end of their life–and between the tapered wear and the thinness, we were experiencing a lot of knockback in some situations, particularly if we were working the curbs hard on track. That meant either a long pedal on application, or the need to sneak the left foot over for a little brake tap on a straightaway to reset the pads.
Ultimately, it really was just time for some fresh pads, and we installed a set before heading out for the Tire Rack SCCA Solo Nationals in Lincoln, Nebraska–a trip that will also include a stop at NCM Motorsports Park for the Holley LSFest Road Course Challenge before we return home to Florida.
Swapping out the pads on the six-piston front and four-piston rear Wilwood Superlite calipers is a piece of cake, only requiring one specialized tool in the form of a 12-point, 13mm socket to remove the two front caliper bolts. Simply pop off those calipers, remove the retaining pins (careful you don’t lose the pin retaining clips), retract the pistons and slide in the new pads. The rear is even easier, not even requiring the caliper to be removed.
Replacing the pads takes only a few minutes, and you’ll be ready to bed them in no time. Bedding is an important step in the installation of new pads that shouldn’t be sklpped, as the torque characteristics and feel of the pads will change somewhat after a proper bedding.
Bedding fresh pads should include a full dynamic heat cycle of the brakes, followed by a progressive cooling back to ambient temperatures. Dynamic heating is important, because unlike static oven heating, this dynamic process will produce the specific surface heating and friction material transfer that comes from a proper bedding cycle.
The process we like is to perform several decelerations from highway speeds–60 mph or so–to 10-15 mph. It’s important you not come to a full stop or you can introduce hot spots into the rotors. The number of decelerations should be sufficient to produce adequate brake temperature, or to produce fade. So figure on eight to 10 hard decelerations, or when you start to feel fade, whichever comes first.
Once the brakes are thoroughly heated, they need to return to as close to ambient temps as possible, so keep air flowing around them by keeping the car moving at a low speed without hitting the brakes. Ideally you should return the brakes to a temperature you could comfortably touch with your hand before allowing the car to be stationary.
In our case, we switched from the Wilwood BP30 pads to a slightly more aggressive BP40 track compound, so we never got to the point of fade during bedding (nor are we likely to on track, as the BP40s are highly track-friendly and noted for their consistency).
The new BP40 pads (left) and the worn BP30 pads (right) we replaced.
We’re excited to try them in anger. They seem to like a little bit of heat to work their best, but even at autocross temps, they’re grippy and consistent. They also seem to take a slightly lighter foot to produce some impressive deceleration than the BP30s did, which we actually like. We like modulating the brakes with our toe instead of our whole foot. Your tastes may vary, but we’re excited to give these new pads a full workout on the autocross course and track.
While we were messing with the brakes, we also slapped on a set of Wilwood temperature indicators. These handy, adhesive stickers feature a graduated, thermally reactive gauge that shows the maximum temperature that the surface they’re applied has reached. These can be useful for fine tuning brake bias adjustments, or even discovering whether you have too much–or too little–brake on the car.
While we were replacing the pads, we also took the opportunity to replace the front hubs, because the left-front hub had straight up broken off the flange. Yikes. We caught that one right in time.
Ideally, we’d have replaced the front hubs with a set of SKF X-Tracker units, which are the indestructible hotness for Corvettes, but we didn’t have time to track a set down. So we opted for an American-built set of Timken hubs, which are regarded to be a pretty good choice. The set that broke were Moog branded, but they had been on there since we purchased the car, and we feel like nearly four years of heavy pounding is a pretty good lifespan, given their less-than-stellar reputation.
We did swap the ARP extended wheel studs from our old hubs to the new ones, however. When taking the factory studs out, please don’t use a percussive extraction method (also known as whacking them with a hammer). This places a lot of impact load on the flange, and, as we know, they break eventually, so don’t encourage that behavior. We used a balljoint separator tool, but any number of pullers or stud removers will do the job just fine.
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